it's a miracle. >> his unlikely role in an indiana nun's path to sainthood. >>> revealing investigations. fascinating characters. stories with impact. this is "cnn presents" with tonight's host, randi kaye and dr. sanjay gupta. >> good evening. we begin tonight with this unbelievable story of how u.s. soldiers were used as human guinea pigs. during the cold war, the military embarked on this top-secret program to test chemical and biological weapons. >> the researchers used animals, but believe it or not, they also used humans, volunteers from the army who had no idea what they were signing up for. >> nearly half a century later, some of these human guinea pigs, well, they're emerging from the shadows with disturbing stories about what the military did to them and how they're being treated now. ♪ >> i enlisted, joined at 18 years of age. it was the height of the vietnam war era and really felt a sense of duty to my country to go and serve. >> i went straight to ft. bragg. it was the thing to do. it was my duty as an american. >> i was drafted and i was placed in the 85th
